[JS] 프로그래머스 / 코딩테스트 입문 / 가장 많이 받은 선물

문제

프로그래머스

정답

function solution(friends, gifts) {
  const giftsSign = {};
  const giftsList = {};

  friends.forEach(friend => {
    giftsSign[friend] = 0;
    giftsList[friend] = [];
  });

  gifts.forEach(gift => {
    const [giver, taker] = gift.split(" ");
    giftsSign[giver] += 1;
    giftsSign[taker] -= 1;
    giftsList[giver].push(taker);
  });

  let answer = {};
  friends.forEach(friend => {
    answer[friend] = 0;
  });

  for (let i = 0; i < friends.length; i++) {
    for (let j = i + 1; j < friends.length; j++) {
      const A = friends[i];
      const B = friends[j];
      const giveCount = giftsList[A].filter(friend => friend === B).length;
      const takeCount = giftsList[B].filter(friend => friend === A).length;

      if (giveCount > takeCount) {
        answer[A] += 1;
      } else if (giveCount < takeCount) {
        answer[B] += 1;
      } else {
        if (giftsSign[A] > giftsSign[B]) {
          answer[A] += 1;
        } else if (giftsSign[B] > giftsSign[A]) {
          answer[B] += 1;
        }
      }
    }
  }

  const totalGiftCountArr = Object.values(answer);

  return totalGiftCountArr.length > 0 ? Math.max(...totalGiftCountArr) : 0;
}